JP3716062B2 - Surplus steam recovery device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surplus steam recovery device in a private power generation facility or the like having a condensate turbine generator.
[0002]
[Prior art]
A conventional technique will be described with reference to FIGS.
[0003]
An example of the conventional steam plant is shown in FIG. 2. As shown in FIG. 2, the regulating valve 3 for adjusting the introduction of the main steam, the extraction turbine high pressure section 2 a, the extraction turbine low pressure section 2 b, the extraction turbine high pressure section 2 a and the extraction turbine low pressure section. A bleed pressure regulating valve 6 communicated with 2b, a generator 15 driven coaxially with the bleed turbine high pressure portion 2a and the bleed turbine low pressure portion 2b, a condenser 5 for receiving exhaust gas from the bleed turbine low pressure portion 2b, It comprises an extraction line 1 that receives exhaust from the extraction turbine high-pressure section 2a and guides it as factory steam and the like, and an atmospheric discharge valve 4 for main steam that is connected to the main steam supply line.
[0004]
In such a conventional steam plant, when surplus steam is generated due to depletion of factory steam or the like, the processing of the surplus steam (turbine extraction) is performed when the power generation amount constant control of the generator 15 is controlled. When the inflowing steam increases, the regulating valve 3 is throttled and the main steam becomes surplus, so that the surplus main steam is released to the atmosphere by opening the atmospheric discharge valve 4.
[0005]
Further, as shown in FIG. 3, instead of providing the atmospheric release valve 4 of FIG. 2, instead of this, the main steam supply line and the extraction line 1 are connected by a communication line via a bypass adjustment valve 7, In the case where the extraction line 1 is provided with an extraction air release valve 8, the bypass adjusting valve 7 and the atmosphere release valve 8 are opened, and excess main steam is partially passed through the extraction line 1 to the atmosphere. The discharge valve 8 is discharged into the atmosphere to deal with.
[0006]
Furthermore, as shown in FIG. 4, the atmospheric discharge valve 4 instead of the main steam atmospheric release valve 4 of FIG. 2, the bypass adjustment valve 7 of FIG. 9 is used, and the atmospheric pressure condenser 9 is connected to the extraction line 1 via the regulating valve 16 so that excess steam is recovered by the atmospheric pressure condenser 9.
[0007]
[Problems to be solved by the invention]
As described above, in the conventional system, when surplus steam is generated due to a rapid decrease in factory steam, the main steam is discharged from the main steam supply line to the atmosphere as it is or depending on the form of the plant, or via the extraction line. Then, it has been dealt with by releasing into the atmosphere or condensing with an atmospheric pressure condenser.
[0008]
However, among these treatment methods, in the case of release to the atmosphere, there is a problem of noise along with the loss of a large amount of steam (pure water), and the method of recovering excess steam using an atmospheric pressure condenser is accompanied by an increase in equipment costs. There is a problem that the amount of cooling water required increases.
[0009]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems caused by the prior art, and to provide an efficient surplus steam processing means that is economical and has good maintenance.
[0010]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problem, and a calculator for calculating the steam flow rate of the extraction turbine low-pressure section by inputting the lift of the extraction pressure regulating valve of the extraction turbine or the pressure after the first stage of the extraction turbine low-pressure section. And a regulating valve provided in a bypass line connecting the extraction line and the main condenser, a vacuum gauge for detecting the degree of vacuum of the main condenser, and a release valve for releasing excess air from the extraction line to the atmosphere The calculator provides a recovery device for excess steam in the extraction turbine that receives a signal from the steam load that flows through the extraction line and a signal from a vacuum gauge, and outputs an opening / closing signal for the regulating valve or the discharge valve. Estimate the allowable steam flow rate from the lift of the bleed pressure regulating valve or the pressure after the first stage of the bleed turbine low pressure section and know the allowable maximum flow rate, and know the generation of excess steam with the steam load sudden decrease signal of the bleed line Then, open the bypass line adjustment valve and absorb the surplus steam through the bypass line with the main condenser, and monitor the vacuum condition of the main condenser with a vacuum gauge. The regulating valve of the line is closed and the discharge valve is opened, so that excess steam is released to the atmosphere.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIG. In addition, about the same part as the above-mentioned conventional thing, the same code | symbol is attached | subjected and shown in the figure so that a mutual relationship may be understood easily.
[0012]
Reference numeral 1 denotes a bleed line, which communicates with factory equipment (not shown) and supplies so-called factory steam. 2a is an extraction turbine high-pressure part, and the extraction line 1 starts from here. Reference numeral 2b denotes a bleed turbine low pressure portion which communicates with the bleed turbine high pressure portion 2a via the bleed pressure regulating valve 6 and its exhaust port communicates with the main condenser 5.
[0013]
The extraction turbine low-pressure part 2b is axially coupled to the extraction turbine high-pressure part 2a on one end side, and drives the generator 15 axially coupled to the other end side in cooperation with the extraction turbine high-pressure part 2a.
[0014]
8 is a discharge valve that opens and closes the atmospheric discharge path that communicates with the extraction line 1, 10 is a pressure gauge that detects the pressure after the first stage of the extraction turbine low-pressure section 2b, and 11 is the extraction line 1 and the main condenser. An adjustment valve 12 that opens and closes a bypass line 17 that connects to 5 is a vacuum gauge that detects a vacuum pressure in the main condenser 5.
[0015]
An arithmetic unit 14 receives the lift signal of the bleed pressure regulating valve 6 and / or the pressure signal after the first stage of the bleed turbine low pressure portion 2b from the pressure gauge 10, and estimates the steam in the bleed turbine low pressure portion 2b as an estimated value. When the flow rate is calculated and the calculation result is less than the maximum flow rate in the extraction turbine low-pressure part 2b, when the steam load rapid decrease signal 13 of the extraction line 1 is received, an open signal is sent to the regulating valve 11 and the bypass line 17 is opened. Put it in a state.
[0016]
Further, the calculator 14 is configured to receive a signal from the vacuum gauge 12 and issue a command to close the regulating valve 11 and open the discharge valve 8 when this indicates a low vacuum of, for example, 650 mmHg or less.
[0017]
Since the present embodiment is configured as described above, for example, when a signal such as a paper out is generated in a paper mill and a steam load rapid decrease signal 13 for suddenly reducing the factory steam load supplied via the extraction line 1 is generated, As a result of calculation by the calculator 14 in relation to the lift of the pressure regulating valve 6 and / or the steam flow rate of the extraction turbine low-pressure part 2b estimated from the pressure after the first stage of the extraction turbine low-pressure part 2b, the adjustment valve 11 is opened. Then, surplus steam is supplied to the main condenser 5 via the bypass line 17 and recovered here.
[0018]
In this case, since the turbine output, that is, the electric power generated by the generator 15 is constant, the steam flow rate at the turbine inlet is not changed, and no surplus of the main steam is generated even in a recovery boiler with poor followability.
[0019]
While the main condenser 5 is used to continue the recovery of the excess steam as described above, the vacuum drop of the main condenser 5 is monitored by the vacuum gauge 12, and the main condenser 5 is kept at a constant vacuum value. For example, when the pressure reaches 650 mmHg or less, the adjusting valve 11 is closed by a command from the computing unit 14, and instead, the discharge valve 8 is opened to switch the excess steam to the atmosphere.
[0020]
That is, in this embodiment, attention is paid to the fact that the main condenser 5 has a margin during normal operation in this kind of turbine plant (generally a bleed condensate turbine), and surplus steam at the time of a sudden decrease in factory steam load is used as factory steam. In the middle of the bleed line 1 as the supply line, the bypass line 17 introduces and recovers to the main condenser 5 having a margin, thereby processing economically without affecting the generated power.
[0021]
Although the present invention has been described with reference to the illustrated embodiment, the present invention is not limited to this embodiment, and it goes without saying that various modifications may be made to the specific structure within the scope of the present invention. Absent.
[0022]
【The invention's effect】
As described above, according to the present invention, it is not necessary to provide a special atmospheric pressure condenser for recovering surplus steam and peripheral equipment such as a cooling water facility associated therewith, and the cost and maintenance for installing these facilities are unnecessary. There is an effect.
[0023]
In addition, since the excess steam is not always released to the atmosphere, the frequency of the atmosphere releasing operation is greatly reduced, and the steam (pure water) can be saved.
[Brief description of the drawings]
FIG. 1 is a system diagram of a surplus steam recovery apparatus according to an embodiment of the present invention.
FIG. 2 is a system diagram of a conventional general power generation facility.
FIG. 3 is a system diagram of a conventional processing apparatus for surplus steam released into the atmosphere.
FIG. 4 is a system diagram of a conventional surplus steam processing apparatus using an atmospheric pressure condenser.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Extraction line 2a Extraction turbine high pressure part 2b Extraction turbine low pressure part 3,7,11,16 Regulating valve 4,8 Release valve 5 Main condenser 6 Pressure regulating valve 9 Atmospheric pressure condenser 10 Pressure gauge 12 Vacuum gauge 13 Steam load rapid decrease signal 14 Calculator 15 Generator 17 Bypass line

Claims (1)

Provided in the bypass line connecting the extraction line and the main condenser, by inputting the lift of the extraction pressure regulating valve of the extraction turbine or the pressure after the first stage of the extraction turbine low-pressure part and calculating the steam flow of the extraction turbine low-pressure part A regulating valve, a vacuum gauge for detecting the degree of vacuum of the main condenser, and a discharge valve for releasing excess air from the extraction line to the atmosphere, wherein the computing unit has a rapid decrease signal of the steam load flowing through the extraction line; An apparatus for recovering surplus steam in an extraction turbine, wherein a signal from a vacuum gauge is received and an opening / closing signal for the regulating valve or the discharge valve is output.

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